One type of extracorporeal blood processing is an apheresis procedure in which blood is removed from a donor or donor/patient, directed to a blood component separation device (e.g., centrifuge), and separated into various blood component types (e.g., red blood cells, white blood cells, platelets, plasma) for collection or therapeutic purposes. One or more of these blood component types are collected (e.g., for therapeutic purposes), while the remainder are returned to the donor or donor/patient.
A number of factors affect the commercial viability of an apheresis system. One factor relates to the operator of the system, specifically the time and/or expertise required of an individual to prepare and operate the apheresis system. For instance, reducing the time required by the operator to load and unload the disposables, as well as the complexity of these actions, can increase productivity and/or reduce the potential for operator error. Moreover, reducing the dependency of the system on the operator may lead to reductions in operator errors and/or to reductions in the credentials desired/required for the operators of these systems.
Donor-related factors may also impact the commercial viability of an apheresis system and include donor convenience and donor comfort. For instance, donors typically have only a certain amount of time which may be committed to visiting a blood component collection facility for a donation. Consequently, once at the collection facility the amount of the donor's time which is actually spent collecting blood components is another factor which should be considered. This also relates to donor comfort in that many view the actual collection procedure as being somewhat discomforting in that at least one and sometimes two access needles are in the donor throughout the procedure.
Performance-related factors continue to affect the commercial viability of an apheresis system. Performance may be judged in terms of the “collection efficiency” of the apheresis system, which may in turn reduce the amount of donation time and thus increase donor convenience. The “collection efficiency” of a system may of course be gauged in a variety of ways, such as by the amount of a particular blood component type which is collected in relation to the number of this blood component type which passes through the apheresis system. Performance may also be evaluated based upon the effect which the apheresis procedure has on the various blood component types. For instance, it is desirable to minimize the adverse effects on the blood component types as a result of the apheresis procedure (e.g., reduce platelet activation).
Another performance-related factor can be the end quality of the collected blood component. For example, if red blood cells are the component to be collected, it is generally desirable that such red blood cells be leukoreduced by the removal of white blood cells or leukocytes. White blood cells can present problems to the ultimate recipient of the collected blood component. Transfused products containing white blood cells can provoke immunogenic reactions and viral diseases.
In the past, filters have been used to remove leukocytes from collected blood products or components. For example, U.S. Pat. No. 5,954,971 discloses the use of a filter with an apheresis system for filtering a blood component prior to collection.